Members of Columbia investigative board arrive in Texas

Members of the independent board investigating the Columbia disaster arrived Tuesday morning to get a firsthand look at the debris being collected from across a vast stretch of countryside.

"One of the first things we had to do is go out and look at some of the debris. It makes the accident more personal to us. This prevents it from becoming an abstract event," said retired Navy Adm. Harold W. Gehman Jr., chairman of the commission. "I know that we won't go out and solve the mystery this morning."

Search crews found more human remains early Tuesday, said Sabine County Sheriff Tommy Maddox, but he refused to elaborate.

On Monday, investigators located the spacecraft's nose cone in a heavily wooded area. Officials waited on Tuesday for the Environmental Protection Agency to remove the cone, which was partially buried in a hole 20 feet across.

The nose section, one of the largest and most recognizable parts found so far, could provide insight into how the shuttle disintegrated over Texas on Saturday, killing all seven astronauts. It was found a few miles from Hemphill, a town of about 1,200 people that is 130 miles northeast of Houston.

Resident Nathan Ener told CNN that the nose section was driven about 4 feet into the ground. "There's four or five big chrome pedals, wire, electrical wire, dashboard. It didn't look like anything had been burned or anything," Ener said.

About 20 people connected to the independent board arrived in Nacogdoches by helicopters from Barksdale Air Force Base in Louisiana. Gehman said the commission has 20 teams of experts in various fields working independently.

"We have no timetable. Our first imperative is to get it right. But we also have three astronauts in space who are counting on us," Gehman said, referring to the international space station crew members who need a ride back to Earth aboard a shuttle or a Russian vehicle. "We are not looking for anything in particular today, but any debris that is up range would be of great interest."

On Monday, NASA shuttle program manager Ron Dittemore said NASA is particularly interested in heat-protection tiles or other pieces that may have fallen from Columbia as far west as New Mexico, Arizona or California. The FBI was checking reports of possible debris in Arizona.

Some 12,000 pieces of debris had been collected in the region by late Monday afternoon. Human remains were reported at 15 locations in Nacogdoches County alone.

Gehman and the investigative team visited a few debris sites in a van caravan outside Nacogdoches.

The first site was an electrical power substation eight miles west of the city. A scorched metal box about the size of a VCR had landed in the soft red dirt. It appeared to be an electronic component, but investigators were unable to immediately identify it.

A few miles farther west, Gehman's caravan stopped to inspect debris that had fallen by road, narrowly missing houses and a closed restaurant.

The debris consisted of 3-foot feathery strips of black material reinforced with aluminum. Military crews logged the locations of the debris with GPS satellite equipment and evaluated it for hazardous and radioactive contamination with backpack monitoring devices. Then they wrapped the debris for removal in black plastic bags.

"The first thing that occurs to me is that this could have come from the back of the shuttle's orbital maneuvering system," said Bryan D. O'Connor, a NASA associate administrator. He knelt beside the debris _ a curved strip of material made from lightweight black carbon epoxy fibers.

"Seeing the debris demonstrates the destruction and the chaos of it," Gehman said.

Frequently during the inspection he looked up into the partly cloudy sky over East Texas and with his arms marked Columbia's flight path toward and how pieces of the disintegrating orbiter came to rest where he was standing.

"How does something so light as this debris make it this far east?" he asked. "Some of this is very light stuff. It will be interesting when we get a geographical plotting of all the debris and factor in the weight and density of the material."

The pieces are being gathered from an area larger than West Virginia, stretching west to east 380 miles from Eastland, Texas, to Alexandria, La., and north-south 230 miles from Sulphur Springs, Texas, to metropolitan Houston.

"We'll be finding stuff months down the road. I'd say hunting season is when people will be picking stuff up, or we'll never find it at all," said Calvin Turner, chief deputy in Vernon Parish, La.

The debris field includes the big Toledo Bend Reservoir on the Texas-Louisiana state line, where divers using sonar were searching for what authorities believe is a car-size chunk. That piece had not yet been located Tuesday. "The water is approximately 100 feet deep in that area," Maddox said.